Electrosurgery refers to surgical procedures that pass high frequency, alternating electrical current through body tissues to cut or coagulate the tissues. Electrosurgical instruments or tools such as electrosurgical electrodes are used in these surgical operations to cut, coagulate and cauterize the tissue of a patient. The electrodes conduct the high frequency alternating electrical current from a generator to the patient to perform these operations. The generator is the source of the electricity for the surgical procedure. Because standard electrical current alternates at a frequency of sixty cycles per second (60 Hz), which could cause excessive neuromuscular stimulation and possibly electrocution if used, the generator takes sixty cycle current and increases the frequency to over 300,000 cycles per second (300,000 Hz). At this frequency, the electrical energy can pass through the patient with minimal neuromuscular stimulation and no risk of electrocution. Additionally, the generators are able to produce a variety of electrical waveforms. A constant waveform, which produces heat very rapidly, is generally used to vaporize or cut body tissue. An intermittent waveform produces less heat and is generally used to coagulate body tissue. Several different waveforms may used in an electrosurgical procedure to achieve different effects.
As described above, electrosurgical electrodes are used to cut or coagulate the body tissue in an electrosurgical procedure. Many sizes and shapes of electrosurgical electrodes such as blades, scalpels, needles, wire forms, balls and probes are available. Most electrosurgical electrodes are made of metal, typically stainless steel. Generally, a portion of the electrode is sheathed or encapsulated with an insulative material such as a plastic material. The electrodes are typically inserted into and connected to a handpiece for manipulating the electrode during surgery.
The working surface of the electrosurgical electrode or the exposed end of the electrode is not encapsulated with plastic or any type of electrically insulative material. The working surface generates heat and therefore is subject to high temperatures during use. The high temperature causes the body tissues to tend to stick to the working surface of the electrode. Specifically, the elevated temperature of the electrode causes charred tissue, commonly called “eschar,” to adhere or stick to the working surface of the electrode. The buildup of tissue or eschar on the working surface of the electrode negatively affects the performance of the electrode during surgery. In particular, a buildup of tissue on the electrode reduces the transfer of energy to and from the electrode which decreases the cutting effectiveness of the electrode. Additionally, the tissue buildup may obscure the vision of the surgeon and therefore make it more difficult to perform the surgery.
As a result, efforts are made during surgery to keep the working surface of the electrode clean. Such cleaning methods include rubbing, brushing or scraping the electrode surface against a scouring pad or other suitable cleaning device. The continuous cleaning of the surface of the electrode, however, prolongs the surgical procedure which is not desirable. Therefore, the surgeon is left with the options of replacing the electrode during surgery, accepting reduced performance of the electrode, or expending valuable time and energy in an attempt to thoroughly clean the surface of the electrode with an abrasive pad. If the surgeon must clean the surface of the electrode with an abrasive pad, as while scouring the coated surface of the blade, the surgeon must spend additional time and attention to not damage or wear through the protective coating.
One method used to solve the problem of tissue or eschar buildup on the surface of the electrode is to coat the surface of the electrode with a non-stick or surface release coating. The non-stick or release coating minimizes the sticking or adherence of the tissue on the surface of the electrode and enables the built up tissue to be removed more easily and efficiently from the surface.
Several different types of non-stick coatings have been used or suggested for application to electrosurgical electrodes. Some of the different non-stick coatings or materials include fluorinated hydrocarbon materials, polytetrafluoroethylene, perfluoro-alkoxy, flexible silicone elastomers, ceramic composites, paralyene silane polymers and other suitable non-stick coatings. Different methods exist for applying the non-stick coating to the surface of the electrosurgical electrodes. However, the non-stick or release coatings have varying degrees of electrically insulative qualities, and therefore, may change and/or impair the electrical conductivity of the surface of the electrodes. Some of such coatings are thinner (due to their inherent technical limitations and/or cost of production reasons) and thus posses less than optimum electrical and/or insulative properties. Other coatings provide discontinuous protection of the underlying metal blade and may contain micro fractures, holes and/or “holidays.” It should be appreciated that coating areas of reduced thickness and areas wherein the coating is missing may alter the electrical insulative or surface characteristics of the electrical energy emitted from the surface of the coating, thus affecting the quality and consistency of the use of the blade. Such altered electrical insulative properties present an erratic and potential inconsistent function of the use of the electrosurgical device as a surgical tool.
Moreover, certain of these non-stick coatings, particularly the fluoropolymers, may break down and emit harmful byproducts as the coated portion or portions of the electrosurgical electrode are heated to temperatures above 500° F. (260° C.). In addition to breaking down at temperatures above 500° F. (260° C.), as certain of these non-stick coatings approach 500° F. (260° C.), micro-fractures or fissures in the coating surface take place. These micro-fractures provide additional areas for eschar or carbonized organic matter to adhere to the electrosurgical device. As the coating breaks down due to thermal overheating of specific areas of the blade, particularly the edges and tip of the blade, the electrical insulative quality of the original coating is diminished and eventually destroyed. Accordingly, the user will need to change the electrical settings of the electrical generator or need to change to a new blade to achieve consistent end use results.
Another issue associated with surgical instruments such as electrosurgical electrodes is the cleanliness of the working surface and other surfaces of the electrode as the electrode contacts tissue and other parts of the body. The tissue or eschar buildup on the working surface of the electrode creates an environment where bacteria and other harmful organisms may cultivate and be introduced into the body during the surgical process. Furthermore, any gaps between the plastic sheath and the electrode or any fractures, fissures or other defects in the plastic sheath enables bacteria and other organisms to get underneath the plastic sheath and also into and grow in the fractures, fissures and defects or other interstices in the plastic sheath. This warm environment also promotes organism and bacteria growth. This further promotes the growth of the bacteria and the harmful organisms which may migrate to the surface of the electrode or to the patient. Bacteria forming on the eschar which in turn enters a patient's body during a surgical procedure can cause significant difficulties and complications for the patient after the surgical procedure is complete. As a result, minimizing the buildup of tissue or eschar and thus minimizing the growth of bacteria and other organisms on the electrode surface (and between the insulating sheath and the electrode shaft) is desirable to enable the electrode to be used multiple times to minimize and/or prevent infections or other related complications from developing in a patient following surgery.
Accordingly, there is a need for an improved electrosurgical device such as a single use or multi-use electrosurgical electrode and method of manufacturing same which minimizes the buildup of tissue on the substrate or working surface of the electrode during storage, use or pauses in the use of the electrode. Additionally, there is a need for an improved electrosurgical device which has superior easy-to-clean characteristics if the user desires to or must clean the electrosurgical device for multiple uses and/or store the previously used blades for future uses.